Determine status of exchange mailbox vb.net

Hello fellow experts,

I'm currently writing a vb.net 2.0 consoleapp that will cycle through active directory user accounts and add/remove them to/from some distrobution lists. No problems doing that.
Now for the question. in the exchange management snap-in there is a column "StorageLimits" that says whether the mailbox is below limit, disabled ect.
Can i access that info using the directoryentry object?
What AD property is that information stored in?

PS: I want to add the users to the Distro if their mailbox is below limit,
and I want to remove them from the distro if their mailbox is disabled.